Recommendation 2.1
➤ Adjuvant fluoropyrimidine-only chemotherapy is not routinely
recommended for patients with deficient mismatch repair (dMMR)/
microsatellite instability (MSI) tumors. (Strong recommendation;
EB-H-M)
Qualifying statements:
▶ For patients with dMMR or MSI and T4 tumors and/or other high-
risk features (with the exception of poor differentiation), oxaliplatin
containing chemotherapy may be considered (see Recommendation
3.1, qualifying statements). This qualifying statement is based on
indirect evidence of a DFS benefit with the addition of oxaliplatin in
the population of patients with stage II or stage III colon cancer in the
MOSAIC trial.
▶ Poor differentiation is not considered a high-risk prognostic factor in
patients with dMMR or MSI tumors.
▶ Patients with proficient mismatch repair (pMMR)/microsatellite stable
(MSS) tumors are included within Recommendations 1.1 to 1.4.
Recommendation 3.1
➤ There is insufficient evidence to routinely recommend the addition
of oxaliplatin to fluoropyrimidine-based chemotherapy for patients
with high-risk stage II colon cancer. (Weak recommendation; EB-
B-L)
Qualifying statements:
▶ The Expert Panel notes the significant time to recurrence benefit with
oxaliplatin-containing ACT in exploratory analyses of the MOSAIC
trial. The Panel recommends a shared-decision making approach to guide
choice of therapy that includes discussion of potential for benefit and
risks of harm with the addition of oxaliplatin to fluoropyrimidine-based
chemotherapy.
▶ As stated in the qualifying statement to Recommendation 2.1, for patients
with dMMR or MSI who have T4 tumors and/or other high-risk features
(with the exception of poor differentiation), when shared decision-making
results in the choice to proceed with ACT, the Expert Panel recommends
oxaliplatin-containing chemotherapy. This statement is based on indirect
evidence of benefit in the combined population of patients with stage II
and III colon cancer.
